Split out vm782-c4 builders

masters/master.tryserver.chromium.mac/slaves.cfg

Index: masters/master.tryserver.chromium.mac/slaves.cfg
diff --git a/masters/master.tryserver.chromium.mac/slaves.cfg b/masters/master.tryserver.chromium.mac/slaves.cfg
index 12fde72dacbf6de1776c465cbc3f45a079b2e1e3..9befcde6abe95f1ee7b920dbd0c74b15c91b0761 100644
--- a/masters/master.tryserver.chromium.mac/slaves.cfg
+++ b/masters/master.tryserver.chromium.mac/slaves.cfg
@@ -33,9 +33,12 @@ def mac():
       'mac_nacl_sdk_build',
   ]
 
-  optional2_slaves = ['vm1025-m4']
-  optional2_builders = [
+  optional2a_slaves = ['vm1025-m4']
+  optional2a_builders = [
       'mac_chromium_compile_rel_ng',
+  ]
+  optional2b_slaves = ['vm782-m4']
+  optional2b_builders = [
       'mac_chromium_variable',
       'mac_chromium_variable_archive',
   ]
@@ -99,13 +102,24 @@ def mac():
   out.extend(
     {
       'master': 'TryServerChromiumMac',
-      'builder': optional2_builders,
+      'builder': optional2a_builders,
+      'hostname': slave,
+      'os': 'mac',
+      'version': '10.9',
+      'bits': '64',
+      'pool': 'mac_optional_rel',
+    } for slave in optional2a_slaves
+  )
+  out.extend(
+    {
+      'master': 'TryServerChromiumMac',
+      'builder': optional2b_builders,
       'hostname': slave,
       'os': 'mac',
       'version': '10.9',
       'bits': '64',
       'pool': 'mac_optional_rel',
-    } for slave in optional2_slaves
+    } for slave in optional2b_slaves
   )
   out.extend(
     {